Two conserved domains with unknown function (DUFs) were found among the CFE proteins from different plant sources. (A) Multiple sequence alignment analysis of GhCFE1A/D and other plant CFE proteins uncharacterized and not functionally analysed from Ricinus communis (RCOM_1063000 and RCOM_0517470), Vitis vinifera (LOC100244739, LOC100267532, and VIT_00006712001), Populus trichocarpa (POPTRDRAFT_833990, POPTRDRAFT_811252, and POPTRDRAFT_771875), and Arabidopsis thaliana (At1g61260 and At5g54300). Accession numbers are listed in the Materials and methods. (B) Phylogenetic analysis of CFE proteins. The Neighbor–Joining tree was generated from the amino acid sequences mentioned above, and the numbers next to each node give bootstrap values from 1000 replicates.